Data acquisition system applied to digital lock-in amplifier

The invention provides a data acquisition system applied to a digital phase-locked amplifier. The data acquisition system comprises a mode switching module, a voltage follower, a single-ended to differential amplification circuit, a variable gain amplification circuit, an anti-aliasing filter circuit, an analog-to-digital conversion circuit, a power supply module, a Kalman filter module and a frequency tracking module which are connected in sequence, the mode switching module controlled by the FPGA, the differential amplification circuit compatible with single-ended and differential signals and the two-stage variable gain amplification circuit are adopted, different circuit conditions are considered, the application range of the circuit is greatly widened, the low-input-noise current feedback amplifier and the anti-aliasing filter are adopted to amplify a large-range signal to the full scale of the analog-digital converter, and the analog-digital converter is high in reliability and high in reliability. The i